add test for operators

.gitignore

+__*/
+.pytest_cache

calculator/operators.py

 """
 Operator module contains the Operator class and a list of standard operators.
 """
+
+
 class Operator:
     """
     Operator class is a binary operator with a symbol, a precedence and an evaluation function.
     """
+
     def __init__(self, symbol, precedence, evaluate_function):
         self.symbol = symbol
         self.precedence = precedence
@@ -16,6 +19,7 @@ class Operator:
     def __call__(self, left, right):
         return self.evaluate_function(left, right)
 
+
 STANDARD_OPERATORS = {
     '+': Operator('+', 1, lambda a, b: a + b),
     '-': Operator('-', 1, lambda a, b: a - b),
@@ -27,6 +31,6 @@ def test_operator():
     """
     Test the Operator class.
     """
-    operator = Operator('%', 1, lambda a, b: a % b)
-    assert repr(operator) == '%'
-    assert operator(15, 4) == 3
+    modulo = Operator('%', 1, lambda a, b: a % b)
+    assert repr(modulo) == '%'
+    assert modulo(15, 4) == 3